Producing isoparaffins and naphthenes from hydrocarbons



A. M. LEAS May 19, 1970 PRODUCING ISOPARAFFINS AND NAPHTHENES FROMHYDROCARBONS Filed Sept. 1967 mm mwczowoo 2ocwmoLu 1 why ww mm INVENTORs G e L M M O n r A why A wow 1 Ow mq P S 1 J ww wm\ EK woo m wh A 223fi rc m ootxm 3893 22:35 N

E QEQEEIJB ATTORNEY United States Patent "ice 3,513,085 PRODUCINGISOPARAFFINS AND NAPHTHENES FROM HYDROCARBONS Arnold M. Leas, 803Bellefonte Princess Road, Ashland, Ky. 41101 Filed Sept. 6, 1967, Ser.No. 665,753 Int. Cl. Cg 13/00 US. Cl. 20860 8 Claims ABSTRACT OF THEDISCLOSURE A method for producing isoparaffinic and naphthenichydrocarbon liquids from hydrocarbon liquids such as coal liquids andpetroleum oils, including subjecting at least a part of the feed to ahydrocracking treatment, separating a light liquid fraction from thehydrocracking product boiling below about 600 F., subjecting the lighthydrocracking product to solvent extraction to separate an aromaticextract from a non-aromatic railinate, recycling at least a part of thearomatic extract to the hydrocracking treatment, passing thenon-aromatic raffinate to a catalytic reforming treatment, fractionatingthe catalytic reforming product to separate a gas, a material boiling inthe gasoline range and a material boiling above the gasoline range,passing the material boiling above the gasoline range to a secondsolvent extraction step to separate the same into an aromatic extractfraction and a non-aromatic fraction, recycling at least a part of thearomatic extract fraction to the hydrocracking step, passing thenon-aromatic rafiinate to a hydrogenation step and recovering anisoparafiinic material from the hydrogenation step. In an alternativeoperation, a highly aromatic feed may be passed, at least in part, to analkylation step, alone or together With aromatic extract from the firstsolvent extraction step, and at least a part of the alkylation productis passed to a hydrogenation step to produce naphthenic hydrocarbons. Instill another alternative form of operation, at least a part of thealkylation product is passed to an isomerization step and the product ofthe isomerization step is passed to the hydrogenation step. Finally, theolefinic materials utilized in the alkylation step may be passed to anisomerization step before passage to the alkylation step.

Field of the invention The present invention rel-ates to a novel processfor the production of isoparaffinic and/or naphthenic hydrocarbons. Moreparticularly, the present invention relates to a process for theproduction of isoparaffinic and/or naphthenic hydrocarbons, particularlyuseful as jet fuels.

Description of the prior art Although a number of refining techniqueshave heretofore been proposed for the preparation of isoparaflinic andnaphthenic hydrocarbons for use as jet fuels and the like, suchtechniques have been quite inflexible since they cannot be readilyswitched from one type of production to the other and ,therefore, areincapable of producing balanced blends of isoparafiins and naphthenes.Secondly, all such processes have been limited to the treatment ofpetroleum oils and no attention has been paid to the production of jetfuels from coal liquids or combinations of coal liquids with petroleumoils.

3,513,085 Patented May 19, 1970 Summary of the invention It is thereforean object of the present invention to overcome the above-mentioneddeficiencies of the prior art. Another object of the present inventionis to provide a novel process for producing naphthenic and isoparaffinichydrocarbons. A still further object of the present invention is toprovide an improved technique for producing isoparafiinic and naphthenichydrocarbons, particularly useful as jet fuels. Another and furtherobject of the present invention is to provide a technique for producingisoparaflinic and naphthenic hydrocarbons which is highly flexible andreadily converted to maximization of one product over the other. Anotherand further object of the present invention is to provide an improvedtechnique for the conversion of coal liquids or coal liquids incombination with petroleum oils to naphthenic and isoparaffinichydrocarbons, particularly useful as jet fuels.

Description of the preferred embodiments The present invention will bebest understood by reference to the accompanying drawing.

In accordance with the present invention, a hydrocarbon liquid feedmaterial, such as liquids derived from normally solid materials such ascoal, shale, tar sand, etc., petroleum crude materials, or mixtures ofsuch liquid hydrocarbons, is introduced to the system through line 10.All or a part of this feed is passed through line 12, controlled byvalve 14, to a hydrocracking unit 16. Hydrocracking products areseparated into a light liquid fraction boiling below about 600 R, whichis discharged through line 18, and a heavy liquid product boiling aboveabout 600 F., which is discharged through line 20. All or a part of thelight hydrocracking product in line 18 may be passed to a solventextraction operation 22. In solvent extraction unit 22, the material isseparated into an aromatic extract fraction, which is discharged throughline 24 and a non-aromatic raflinate fraction discharged through line26. The non-aromatic raifinate from line 26 is passed to a catalyticreforming unit 28. Reformate from the reforming unit is dischargedthrough line 30 to fractionation column 32. In fractionation column 32,the reformate is separated to produce a gas through line 34, a gasolinerange boiling fraction discharged through line 36, and a fractionboiling above gasoline, discharged through line 38. The material fromline 38 is passed to a second solvent extraction unit 40. Solventextraction unit 40 also employs an aromatic selective solvent andseparates the material into an aromatic extract discharged through line42 and a non-aromatic raffinate discharged through line 44. The aromaticextracts from lines 24 and 42 may be recycled to the hydrocrackerthrough line 46 and valve 48. The non-aromatic raf finate in line 44 ispassed to hydrogenation unit 50 Where it is hydrogenated to produce aproduct containing substantial amounts of isoparaflins. The naphthenicmaterials may be preduced in one of several Ways. A highly aromatic feedmaterial, passing through line 10, may be passed through line 52 andvalve 54 to alkylation unit 56. A light olefinic material may beintroduced to the alkylation unit through line 58, line 60 and valve 62.In alkylation unit 56, the aromatics are converted to alkyl aromaticswhich may be discharged through line 64 and valve 66 to hydrogenationunit 50 or they may be discharged through line 68 and valve 70 toisomerization unit 72. The isomerization product may then be dischargedthrough line 74 to hydrogenation unit 50. The naphthenic products ofhydrogenation unit 50 may be discharged through line 76. Hydrogenationunit 50 is shown as a dual unit wherein isoparaffins and naphthenes areproduced from two different hydrogenation sections. However, thehydrogenation unit may be a single hydrogenation operation. It is alsopossible, in accordance with the present invention, to feed light normalolefins to line 78 and valve 80 to isomerization unit 72. Inisomerization unit 72, these normal olefins may be converted toisoolefins which are discharged through line 82. The isoolefins may thenbe used to alkylate the aromatic materials in alkylation unit 56. Thisproduct will then be ultimately hydrogenated to produce naphthenes. Theisomerization unit may also be a two-unit operation, particularly whereolefins are to be isomerized and aromatic materials are to be isomerizedat the same time.

The hydrocracking Zone may be a conventional unit operated in two stagescontaining conventional hydrocracking catalysts, including nickel-oxideor nickel sulfide on silica-alumina, cobalt-molybdenum on alumina, aprecious metal on silica-alumina, etc. Such a two-stage unit shouldemploy a more active catalyst in the second stage. Operation of thehydrocracking units is normally at a pressure of at least about 500p.s.i.g., and preferably 1000 to 3500 p.s.i.g., a temperature from about400 to 1200 F., and preferably 700 to 850 F., a hydrogen feed rate ofabout 100 to 20,000 s.c.f. per barrel, and preferably 2,000 to 10,000s.c.f. per barrel, and a liquid hourly space velocity of about 0.1 to5.0, and preferably 0.3 to 5.0.

The two aromatic selective solvent separations are also conventional andmay employ solvents such as sulfur dioxide, furfural, phenol-water,sulfolane, etc.

The catalytic reforming operation is preferably carried out in thepresence of a conventional reforming catalyst, such as a precious metalon alumina. However, the reforming is preferably a low severitytreatment at a temperature of about 500 to 850 F. Other suitableconditions include a pressure of about to 1,000 p.s.i.g., and preferably50 to 200 p.s.i.g., a liquid hourly space velocity between 1 and 20, andpreferably 1 and 10, and a hydrogen rate of about 100 to 10,000 s.c.f.per barrel of feed, and preferably 2,000 to 10,000 s.c.f. per barrel.

The alkylation treatment may be carried out in the presence of a solidsilica-alumina catalyst with a boron fluoride promoting agent depositedthereon. Suitable operating conditions include a temperature of about 30to 800 F., and preferably 100 to 450 F., a pressure between about and2,000 p.s.i.g., and preferably 300 to 1,000 p.s.i.g., and a liquidhourly space velocity of about 0.1 to 20, and preferably 0.5 to 2.0.

Hydrogenation may be carried out in the presence of a precious metalsuch as platinum on alumina at a temperature of about 100 to 900 F., andpreferably 200 to 600 F. A pressure of about 0 to 10,000 p.s.i.g., andpreferably 100 to 1,000 p.s.i.g., a liquid hourly space velocity ofabout 0.1 to 10, and preferably 0.5 to 5.0, and a hydrogen feed rate ofabout 100 to 3,000, and preferably 500 to 3,000 s.c.f. per barrel offeed may also be employed.

The isomerization operation may be carried out in the presence of aconventional catalyst such as platinum on silica-alumina and underconditions including a temperature of about 800 to 950 F., a pressure ofabout 50 to 200 p.s.i.g., a liquid hourly space velocity of about 0.5 to10, and a hydrogen rate of about 500 to 3,000 s.c.f. per barrel of feed.

Having described the present invention with reference to a specific flowdiagram and specific examples, it is to be understood that these are notto be considered limiting but that the present invention is to berestricted only by the appended claims.

I claim:

1. A method for producing isoparaffinic hydrocarbons, comprising,subjecting a liquid hydrocarbon feed to a hydrocracking treatment at apressure of at least 500 p.s.i.g., a temperature between about 400 and1200 F., a hydrogen feed rate between about 2000 and 10,000 s.c.f. perbarrel of feed and a liquid hourly space velocity between about 0.1 and5.0, subjecting a light liquid hydrocracking product to the action of anaromatic-selective solvent, subjecting the non-aromatic raffinate of thesolvent extraction step to a reforming treatment at a pressure betweenabout 0 and 1000 p.s.i.g., a temperature between about 500 and 850 F., ahydrogen feed rate between about and 10,000 s.c.f. per barrel of feed,and a liquid hourly space velocity between about 1 and 20, subjecting aheavy liquid fraction of the reforming step to the action of a secondaromatic-selective solvent, and subjecting the non-aromatic raflinate ofthe second solvent extraction to a hydrogenation treatment at a pressurebetween about 0 and 10,000 p.s.i.g., a temperature between about 100 and900 F., a hydrogen feed rate between about 100 and 3000 and a liquidhourly space velocity between about 0.1 and 10.

2. A method in accordance with claim 1 wherein a part of the lighthydrocracking product is subjected to an alkylation treatment at apressure between about 10 and 2,000 p.s.i.g., a temperature betweenabout 30 and 800 F., and a liquid hourly space velocity between about0.1 and 20.

3. A method in accordance with claim 1 wherein the aromatic extract fromthe first solvent extraction is recycled to the hydrocracking treatment.

4. A method in accordance with claim 1 wherein the aromatic solventextract of the first extraction step and the aromatic solvent extract ofthe second extraction step are recycled to the hydrocracking treatment.

5. A method in accordance with claim 1 wherein a part of the hydrocarbonfeed is subjected as an aromatic alkylation treatment at a pressurebetween about 10 and 2,000 p.s.i.g., a temperature between about 30 and800 F., and a liquid hourly space velocity between about 0.1 and 20 andthe alkylation product is then subjected to the hydrogenation treatment.

6. A method in accordance with claim 1 wherein a part of the aromaticextract from the first and second solvent extraction steps is subjectedto an alkylation treatment at a pressure between about 10 and 2,000p.s.i.g., a temperature between about 30 and 800 F., and a liquid hourlyspace velocity between about 0.1 and 20 and the alkylation product issubjected to the hydrogenation treatment.

7. A method in accordance with claim 1 wherein an aromatic feed materialis subjected to an alkylation treatment at a pressure between about 10and 2,000 p.s.i.g., a temperature between about 30 and 800 F., and aliquid hourly space velocity between about 0.1 and 20, the alkylationproduct is subjected to an isomerization treatment at a pressure betweenabout 50 and 200 p.s.i.g. a temperature between about 800 and 950 F., ahydrogen feed rate between about 500 and 3000 s.c.f. per barrel of feed,and a liquid hourly space velocity between about 0.5 and 10, and theisomerization product is subjected to the hydrogenation treatment.

8. A method in accordance with claim 1 wherein an aromatic feed materialis subjected to an alkylation treatment at a pressure between about 10and 2,000 p.s.i.g., a temperature between about 30 and 800 F., and aliquid hourly space velocity between about 0.1 and 20, an olefinic feedcontaining normal olefins is subjected to an isomerization treatment ata pressure between about 50 and 200 p.s.i.g., a temperature betweenabout 800 and 950 F., a hydrogen feed rate between about 500 and 3,000s.c.f. per barrel of feed, and a liquid hourly space velocity betweenabout 0.5 and 10, the isomerization product is utilized in thealkylation treatment and the 6 alkylation product is subjected to thehydrogenation 3,304,340 2/1967 N011 260672 treatment.

References Cited DELBERT E. GANTZ, Primary Examiner UNITED STATESPATENTS A. RIMENS, Assistant Examiner 3,132,087 5/1964 Kelly et a1.30859 5 3,147,206 9/1964 Tulleners 20s 111 3,308,053 3/1967 Kelley et a1260683.65 208-108; 260-68344, 683.53, 683.65, 683.9, 672

